JP2017092060A - Lead frame and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lead frame capable of preventing an electrical short circuit due to plating burr when used for manufacturing a semiconductor device in a lead frame manufactured having a step for performing etching processing after performing plating on a metal plate, and also to provide a method of manufacturing the lead frame.SOLUTION: A lead frame is characterized in that, on the surface on the front side of a metal plate 10, a first plating layer 3 is formed having a protrusion 3-1 protruding laterally from the edge of the surface on the front side of the meal plate, and a second plating layer 4 is formed on the side surface and the surface on the rear side of the metal plate and on the surface on the rear side of the protrusion of the first plating layer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lead frame manufactured by performing a etching process after plating a metal plate and a manufacturing method thereof.

  Conventionally, lead frames are manufactured by etching or pressing a metal plate to form a predetermined shape from the metal plate and performing necessary plating.

  And in the case of manufacturing a lead frame having a step of etching a metal plate, for example, a dry film resist is pasted on both the front and back surfaces of the metal plate, and exposure is performed using a mask on which a predetermined pattern is formed, Development is performed to form resist masks for etching on both the front and back surfaces of the metal plate, and the metal plate is formed into a desired lead frame shape by etching. Thereafter, the resist mask for etching formed on both the front and back surfaces of the metal plate is removed, and a desired plating process is performed.

  By the way, if the plating layer is formed after forming the metal plate in a predetermined shape, the plating layer is formed on the entire upper surface, side surface, and lower surface of the metal plate formed in the predetermined shape, and the plating layer is formed in an unnecessary area. The noble metal that forms is likely to be expensive.

  In order to reduce costs, a lead frame manufactured in the order of steps in which a plating layer is first formed in necessary regions on the upper and lower surfaces of the metal plate and then the shape of the lead frame is formed through etching is desired. .

  However, a technique for manufacturing a lead frame having a process of performing an etching process after performing a plating process on a metal plate is described in, for example, the following Patent Document 1.

  In the lead frame manufacturing method described in Patent Document 1, a resist mask for plating is formed on each of the front side surface and the back side surface of the metal plate, and after performing necessary plating, the resist mask on one side surface is applied. The lead frame shape is formed from the metal plate by dissolving and removing it and etching the exposed metal plate using the previously formed plating layer as an etching resist mask.

JP-A-11-345895

However, in the method of performing etching using the plating layer described in Patent Document 1 as an etching mask, the metal immediately under the plating layer is dissolved and removed, and the plating layer where the metal is dissolved and removed is exposed, and the exposed portion is exposed. It becomes a plating burr and tends to cause cracks and chips.
In particular, in the LED lead frame, if the plating burr formed on the pad portion on the side where the LED element is mounted and the reflective plating layer of the lead portion is cracked, the plating burr cracked during the manufacturing process of the LED package is the lead portion. In addition, there is a risk of causing an electrical short circuit in the bonding wire portion or the LED element portion.

  In order to prevent plating burrs, it is conceivable to form an etching mask for the reflective plating area so as to cover the reflective plating layer to the extent that the metal directly under the reflective plating layer is not dissolved and removed.

However, if a resist mask is formed so as to cover the reflective plating layer to the extent that the metal directly under the reflective plating layer is not dissolved and removed, etching is performed to form a lead frame shape, and then the reflection is removed when the resist mask is removed. The upper surface of the metal plate remains around the plating layer. The upper surface of the remaining metal plate has a lower reflectivity than the reflective plating layer or the reflector resin portion. For this reason, even if the reflector resin portion is formed between the pad portion formed by etching and the lead portion, the LED portion is mounted on the pad portion on the side where the LED element is mounted and the upper surface of the metal plate around the lead portion. The reflectivity of the entire region where the element is mounted is lowered.
Further, when the reflector resin portion is formed between the pad portion formed by etching and the lead portion, the surface of the reflector resin portion on the side where the LED element is mounted is flush with the surface of the reflective plating layer. Even if the upper surface of the remaining metal plate is covered with the reflector resin, the thickness of the reflective plating layer is very thin, so the reflector resin is formed to cover the upper surface of the remaining metal plate around the reflective plating layer. The thickness of the portion is also very thin, and a sufficient reflection effect as a reflector at that portion cannot be obtained.
Moreover, if the thickness of the reflector resin portion formed so as to cover the upper surface of the metal plate remaining around the reflective plating layer is very thin, cracks and chips are likely to occur. And when a crack and a chip | tip arise in the reflector resin part around the plating layer for reflection, the upper surface of a metal plate will be exposed and the reflectance of the whole area | region which mounts an LED element will fall.

  Further, in the technique using the plating layer described in Patent Document 1 as an etching mask, the plating layer is easily affected by the etching solution and unevenness is easily formed on the surface. However, in the LED lead frame, the surface of the plating layer on the side where the LED element on the metal plate is mounted is required to have a glossy Ag plating layer in order to increase the reflectance, but the surface of the glossy Ag plating layer is uneven. When formed, the surface of the glossy Ag plating layer becomes cloudy and the reflectance decreases. In order to suppress the decrease in reflectance, it becomes necessary to polish and smooth the unevenness formed on the surface of the gloss Ag plating surface, and the process becomes complicated accordingly.

  The present invention has been made in view of such a problem, and is used for manufacturing a semiconductor device in a lead frame manufactured by performing a etching process after plating a metal plate. An object of the present invention is to provide a lead frame and a method of manufacturing the same that can prevent electrical shorting due to plating burrs.

  In order to achieve the above object, in the lead frame according to the present invention, a first plating layer having a protrusion protruding laterally from an edge of the front surface of the metal plate is provided on the front surface of the metal plate. A second plating layer is formed on a side surface and a back surface of the metal plate and at least a back surface of the protruding portion of the first plating layer.

  Further, the lead frame according to the present invention has a first plating on the front side surface and the back side surface of the metal plate, each having a protruding portion protruding laterally from the edge of the front side surface and the back side surface of the metal plate. A layer is formed, and a second plating layer is formed on the side surface of the metal plate and at least the metal plate side surface of the protruding portion of the first plating layer.

  In the lead frame of the present invention, it is preferable that the second plating layer is also formed on a side surface of the protruding portion in the first plating layer.

  In the lead frame of the present invention, the first plating layer is a plating layer having Ag as an uppermost layer, and the second plating layer is formed in the order of Ni / Pd / Au or Ni / Pd. A plating layer is preferred.

  In the lead frame of the present invention, it is preferable that the protruding portion of the first plating layer has a protruding length of 15 μm from the edge of the metal plate.

  In the lead frame of the present invention, it is preferable that the side surface of the metal plate is subjected to a roughening treatment.

  The lead frame manufacturing method according to the present invention includes a step of forming a first resist mask for plating on both front and back surfaces of a metal plate, and a step of forming the first resist mask for plating on the front side of the metal plate. A step of forming a first plating layer on a surface; a step of removing the first plating resist mask after forming the first plating layer; and a step of removing the first plating resist mask. And forming a resist mask for etching on the front side and the back side of the metal plate so as to cover at least the first plating layer, and after forming the resist mask for etching, on the front side and the back side of the metal plate, Etching is performed on a region that is not covered with the resist mask for etching, and the first plating layer is lateral to the edge of the front surface of the metal plate. A step of forming the metal plate to have a protruding portion, a step of removing the etching resist mask after performing the etching process, and a step of removing the etching resist mask, Forming a second plating resist mask that covers the front side surface and at least the front side surface of the first plating layer; and forming the second plating resist mask, and then forming a side surface of the metal plate. And a step of forming a second plating layer on the back surface and at least the back surface of the protruding portion of the first plating layer, and after forming the second plating layer, the second plating layer And a step of removing the resist mask for plating.

  The lead frame manufacturing method according to the present invention includes a step of forming a first resist mask for plating on both front and back surfaces of a metal plate, and a step of forming the first resist mask for plating on the front side of the metal plate. A step of forming a first plating layer on the front surface and the back surface, a step of removing the first plating resist mask after forming the first plating layer, and the first plating resist mask. And removing the etching resist mask on the front side and the back side of the metal plate so as to cover at least the front side surface of the first plating layer, and after forming the etching resist mask, Etching is performed on the regions on the front side and the back side of the metal plate that are not covered with the resist mask for etching, and the first plating layer is A step of forming the metal plate so as to have protrusions protruding laterally from the edges of the front side surface and the back side surface of the metal plate, and after performing the etching process, the side surface of the metal plate, Forming a second plating layer on at least the metal plate side surface of the protruding portion of the first plating layer; and, after forming the second plating layer, removing the etching resist mask. And a process.

  In the lead frame manufacturing method of the present invention, the first plating layer is a plating layer having Ag as an uppermost layer, and the second plating layer is made of Ni / Pd / Au or Ni / Pd. It is preferable that the plating layers are formed in order.

  In the lead frame manufacturing method of the present invention, it is preferable that the protruding portion of the first plating layer has a protruding length of 15 μm from the edge of the metal plate.

  In the lead frame manufacturing method of the present invention in which the first plating layer is formed only on the front surface of the metal plate, the etching process and the etching resist mask removal process are further performed. In the meantime, it is preferable to have a step of roughening the surface of the metal plate exposed by the etching.

  Moreover, in the manufacturing method of the lead frame of the present invention in which the first plating layer is formed on the front side surface and the back side surface of the metal plate, the etching process and the second plating layer are further performed. It is preferable to include a step of performing a roughening treatment on the surface of the metal plate exposed by performing the etching during the step of forming.

  According to the present invention, an electrical short due to a plating burr is prevented in a lead frame manufactured by performing a etching process after performing a plating process on a metal plate when used for manufacturing a semiconductor device. A possible lead frame and manufacturing method thereof are obtained.

1 is a cross-sectional view showing a schematic configuration of a lead frame according to a first embodiment of the present invention. FIG. 8 is an explanatory diagram illustrating an example of a manufacturing process in the lead frame manufacturing method illustrated in FIG. 1. It is sectional drawing which shows schematic structure of the lead frame concerning 2nd Embodiment of this invention. FIG. 4 is an explanatory diagram showing an example of a manufacturing process in the lead frame manufacturing method shown in FIG. 3. FIG. 1 is a diagram showing a schematic configuration of a multi-row type LED lead frame according to an embodiment of the present invention, in which (a) is a partial plan view of the arrangement of pads and leads in each lead frame region as viewed from the upper surface side; (b) is a cross-sectional view of the lead frame substrate taken along the line AA shown in (a), and (c) is a cross-sectional view of the lead frame with resin formed in one lead frame region. It is explanatory drawing which shows an example of the manufacturing process of the lead frame for multi-row type LED shown in FIG. It is explanatory drawing which shows an example of the manufacturing process of the lead frame for resin-equipped multi-row type LED using the multi-row lead frame obtained through the manufacturing process shown in FIG. 6, and an LED package.

Prior to the description of the embodiment, the function and effect of the present invention will be described.
In the lead frame of the present invention, a first plating layer having a protruding portion protruding laterally from an edge of the front surface of the metal plate is formed on the front surface of the metal plate. A second plating layer is formed on the surface and at least the back surface of the protruding portion of the first plating layer.

If the second plating layer is formed on the side surface and the back surface of the metal plate and at least the back surface of the protruding portion of the first plating layer as in the lead frame of the present invention, the second plating layer is formed. The protruding portion of the first plating layer is reinforced and supported in a state where it is integrated with the side surface and the back surface of the metal plate and the back surface of the protruding portion of the first plating layer. For this reason, it is possible to prevent the protruding portion from being cracked or chipped as a burr and falling. For example, when the lead frame of the present invention is used as a lead frame for an LED, There is no possibility of causing an electrical short in the lead portion, bonding wire portion, LED element portion, or the like.
In addition, as in the lead frame of the present invention, if the first plating layer is formed to have a protruding portion that protrudes laterally from the edge of the front surface of the metal plate, the front surface of the metal plate is the first surface. 1 does not remain around the plating layer. As a result, in the region where the LED element is mounted on the front side of the metal plate, only the reflective plating layer having a high reflectance is exposed, and the portion having a lower reflectance than the reflective plating layer is not exposed, and the LED element is mounted. Decrease in the reflectivity of the entire area can be prevented.

  In the lead frame of the present invention, the first plating layer has protrusions protruding on the front side surface and the back side surface of the metal plate from the edges of the front side surface and the back side surface of the metal plate. The second plating layer is formed on the side surface of the metal plate and at least the surface of the protruding portion of the first plating layer on the metal plate side.

As in the lead frame of the present invention, if the second plating layer is formed on the side surface of the metal plate and at least the surface on the metal plate side in the protruding portion of the first plating layer, the second plating layer becomes a metal The protruding portion of the first plating layer is reinforced and supported in a state of being integrated with the side surface of the plate and the surface of the first plating layer on the metal plate side. For this reason, it is possible to prevent the protruding portion from being cracked or chipped as a burr and falling, and the plating burr cracked during the manufacturing process of the LED package causes an electrical short circuit in the lead portion, bonding wire portion, LED element portion, etc. There is no fear.
Further, as in the lead frame of the present invention, if the first plating layer is formed to have a protruding portion that protrudes laterally from the edge of the front side surface and the back side surface of the metal plate, The front and back surfaces do not remain around the first plating layer. As a result, in the region where the LED element is mounted on the front side of the metal plate, only the reflective plating layer having a high reflectance is exposed, and the portion having a lower reflectance than the reflective plating layer is not exposed, and the LED element is mounted. Decrease in the reflectivity of the entire area can be prevented.

  Further, as in the lead frame of the present invention, the first plating layer is formed on the front side surface and the back side surface of the metal plate, and the second plating layer is formed on the side surface of the metal plate and the first plating layer. In the lead frame manufacturing process, after forming the first plating layer, the resist mask for etching is formed so as to cover the first plating layer. Can be used also as a second resist mask for plating when forming the second plating layer, and the number of resist masks can be reduced accordingly, the process can be simplified, and the cost can be reduced. It becomes like this.

In the lead frame of the present invention, preferably, the second plating layer is further formed on the side surface of the protruding portion in the first plating layer.
If it does in this way, the migration of the metal in which the 2nd plating layer constitutes the 1st plating layer will be controlled by making the metal which constitutes different in the 1st plating layer and the 2nd plating layer. It becomes easy.

For example, in an LED lead frame, an Ag plating layer is generally formed as a reflective plating layer on the LED mounting surface of each of the lead portion and the pad portion, and a reflector resin portion is formed between the pad portion and the lead portion. In doing so, the surface of the reflector resin portion on the side where the LED element is mounted is formed flush with the surface of the reflective plating layer of the pad portion and the lead portion.
However, if the surface of the reflector resin part is formed flush with the surface of the reflective plating layer of the pad part and the lead part, Ag ions on the uppermost surface of the reflective plating layer formed on the pad part and the lead part are reflected in the reflector resin part. Therefore, there is a concern that the lead portion and the pad portion may cause an electrical short circuit.
However, the configuration in which the second plating layer in the lead frame of the present invention is formed on the side surface of the first plating layer is applied to the LED lead frame, and the reflective plating layer (the first plating of the present invention) is applied. A second plating layer made of a metal (for example, Ni / Pd / Au or Ni / Pd) different from the metal (for example, Ag) constituting the uppermost layer of the reflective plating layer If formed, the metal constituting the second plating layer blocks the movement path of the metal ions constituting the uppermost layer of the reflective plating layer, and the electrical short between the lead portion and the pad portion due to the movement of the metal ions is prevented. Can be suppressed.

In the lead frame of the present invention, preferably, the first plating layer is a plating layer having Ag as the uppermost layer, and the second plating layer is formed in the order of Ni / Pd / Au or Ni / Pd. The plated layer.
Examples of the first plating layer include a configuration of a plating layer made of only Ag, a plating layer formed in the order of Ni / Pd / Au / Ag, and a plating layer formed in the order of base plating / Ag plating. It is done.

In the lead frame of the present invention, preferably, the protruding portion of the first plating layer has a protruding length of 15 μm from the edge of the metal plate.
If the protruding length of the protruding portion of the first plating layer is up to 15 μm from the edge of the metal plate, the protruding portion will not crack and chip as a burr and will not fall and break during the manufacturing process of the LED package There is no possibility that the plating burrs cause an electrical short circuit in the lead portion, bonding wire portion, LED element portion, or the like.

In the lead frame of the present invention, preferably, the side surface of the metal plate is roughened.
If it does in this way, the adhesiveness of the resin part when a reflector resin part and a transparent resin part are formed will improve, for example.

  Note that the lead frame of the present invention described above is formed on the front side surface of the metal plate after forming the first plating resist mask on the front and back surfaces of the metal plate and forming the first plating resist mask. Forming the first plating layer; forming the first plating layer; then removing the first plating resist mask; removing the first plating resist mask; A step of forming an etching resist mask on the back side so as to cover at least the first plating layer, and a region not covered with the etching resist mask on the front side and the back side of the metal plate after forming the etching resist mask On the other hand, performing a etching process and forming the metal plate so that the first plating layer has a protruding portion protruding laterally from the edge of the surface on the front side of the metal plate; A step of removing the etching resist mask after performing the etching process; and a second surface covering the front side surface of the metal plate and at least the front side surface of the first plating layer after removing the etching resist mask. After forming the resist mask for plating, and after forming the second resist mask for plating, the second and second surfaces of the metal plate, and at least the back surface of the protruding portion of the first plating layer, the second And a step of removing the second plating resist mask after forming the second plating layer.

  The lead frame according to the present invention includes a step of forming a first resist mask for plating on both front and back surfaces of a metal plate, and a front surface and a back surface of the metal plate after forming the first resist mask for plating. Forming the first plating layer, forming the first plating layer, then removing the first plating resist mask, removing the first plating resist mask, Etching resist masks on the front and back sides of the metal plate after forming a resist mask for etching on the front side and the back side so as to cover at least the front side of the first plating layer, and forming the resist mask for etching An etching process is performed on the region not covered with the protrusion, and the first plating layer protrudes laterally from the edge of the front surface and the back surface of the metal plate, respectively. After the step of forming the metal plate so as to have an etching process, the second plating layer is formed on the side surface of the metal plate and at least the surface on the metal plate side in the protruding portion of the first plating layer It can manufacture by having a process and the process of removing the resist mask for an etching, after forming a 2nd plating layer.

  In the lead frame manufacturing method of the present invention, preferably, in the step of forming the second plating layer, the second plating layer is also formed on the side surface of the protruding portion of the first plating layer.

  In the lead frame manufacturing method of the present invention, it is preferable that the second plating layer is formed between the step of performing the etching process and the step of removing the resist mask for etching, or the step of performing the etching process. Between the steps, there is a step of performing a roughening treatment on the surface of the metal plate exposed by etching.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First Embodiment FIG. 1 is a sectional view showing a schematic configuration of a lead frame according to a first embodiment of the present invention. FIG. 2 is an explanatory view showing an example of a manufacturing process in the method for manufacturing the lead frame shown in FIG.

For example, as shown in FIG. 1, the lead frame of the first embodiment includes a metal plate 10 formed in a predetermined lead frame shape, a first plating layer 3, and a second plating layer 4. Yes.
The metal plate 10 is made of, for example, a Cu material.
The first plating layer 3 is formed on the front surface of the metal plate 10 and has a protruding portion 3-1.
The protruding portion 3-1 protrudes with a protruding length of up to 15 μm to the side from the edge of the front surface of the metal plate 10.
In addition, the first plating layer 3 includes a plating layer having Ag as the uppermost layer (for example, a plating layer composed only of an Ag plating layer, a plating layer formed in the order of base plating / Ag plating, Ni / Pd / Au Plating layer formed in the order of / Ag).
The second plating layer 4 is formed on the side surface and the back surface of the metal plate 10 and the back surface of the protruding portion 3-1 of the first plating layer 3.
Moreover, the 2nd plating layer 4 is comprised by the plating layer formed in order of Ni / Pd / Au or Ni / Pd.
Note that the second plating layer 4 may also be formed on the side surface of the protruding portion 3-1 of the first plating layer 3 formed on the front surface of the metal plate 10.

  The lead frame of the first embodiment configured as described above is manufactured, for example, as follows. Note that pre-processing and post-processing including chemical cleaning and water cleaning, which are performed in each manufacturing process, are well-known processing, and thus description thereof will be omitted for the sake of convenience.

  First, using a metal plate 10 (for example, a Cu material) that is a base material of the lead frame (see FIG. 2A), a first region is formed on a predetermined region of the front surface of the metal plate 10 and the entire back surface. A plating resist mask 6 is formed, and as a first plating layer 3 in a region exposed without being covered with the first plating resist mask 6 on the front side surface of the metal plate 10, for example, only an Ag plating layer Or a base plating layer and an Ag plating layer, or a Ni plating layer, a Pd plating layer, an Au plating layer, and an Ag plating layer in this order (see FIG. 2B).

  In addition, the formation of the resist mask used in the manufacturing process of the lead frame of the present embodiment and the examples described later is performed by laminating, for example, dry film resists having different dissolution and peeling times on the front surface and the back surface of the metal plate, respectively. This is performed by exposing and developing both front and back surfaces of a dry film resist on both front and back surfaces using a glass mask having a predetermined lead frame shape pattern formed at a predetermined position. Exposure and development are performed by a conventionally known method. For example, by irradiating ultraviolet rays in a state covered with a glass mask, reducing the solubility of the dry film resist portion irradiated with the ultraviolet rays that passed through the glass mask with respect to the developer, and removing other portions, A resist mask is formed. Here, a negative dry film resist was used as the resist. However, for the formation of the resist mask, a positive dry film resist was used to develop a portion of the resist irradiated with ultraviolet rays that passed through the glass mask. The resist mask may be formed by increasing the solubility in the liquid and removing the portion.

  Next, the first resist mask 6 for plating formed on the front and back surfaces of the metal plate 10 is peeled off (see FIG. 2C).

  Next, an etching resist mask 7 having a predetermined shape is formed in a predetermined region covering at least the first plating layer 3 on the front side of the metal plate 10 and in a predetermined region on the back side (see FIG. 2D).

Next, an etching process is performed on regions on the front side and the back side of the metal plate 10 that are not covered with the etching resist mask 7 to form a predetermined lead frame shape. At this time, the metal plate 10 is formed so that the first plating layer 3 has a protruding portion 3-1 protruding from the edge of the surface on the front side of the metal plate 10 with a protruding length of up to 15 μm (FIG. 2). (See (e)).
Next, the etching resist mask 7 formed on the front side and the back side of the metal plate 10 is removed (see FIG. 2 (f)).

Next, a second plating resist mask 8 that covers the front side surface of the metal plate 10 and the front side surface and side surfaces of the first plating layer 3 is formed.
Next, plating is performed, and the first plating layer 3 is not formed on the surface exposed by removing the etching resist mask 7 (for example, the back surface of the metal plate 10 or the front surface of the metal plate 10). And a region that is not etched) and a surface of the metal plate 10 exposed by performing the etching process (for example, a side surface of the metal plate 10, and a recess when the etching process includes a half-etching process). ) And the back side surface of the protruding portion 3-1 of the first plating layer 3, as the second plating layer 4, in order, Ni plating layer, Pd plating layer and Au plating layer, or in order Ni plating layer A Pd plating layer is formed (see FIG. 2 (g)).
In the example of FIG. 2G, the second plating resist mask 8 is formed so as to cover the entire exposed surface of the first plating layer 3. In addition, when manufacturing the lead frame in which the 2nd plating layer 4 was formed also in the side surface in the protrusion part 3-1 of the 1st plating layer 3, the 2nd resist mask 8 for plating is 1st. Of the exposed surface of the plating layer 3, only the front side surface is covered and the side surface is not covered.
Next, the second resist mask 8 for plating is removed (see FIG. 2 (h)).
As a result, the first plating layer 3 (for example, a plating layer composed only of an Ag plating layer or a base plating / Ag plating is formed in this order on the front surface of the metal plate 10 formed in a predetermined lead frame shape. And a protruding portion 3-1 protruding with a protruding length of up to 15 μm to the side of the edge of the surface of the metal plate 10, which is formed in the order of Ni / Pd / Au / Ag. The second plating layer 4 (Ni / Pd / Au, Ni, Pd / Au, etc.) is formed on the side surface (and also the recess) and the back side surface, and the back side surface of the protruding portion 3-1 of the first plating layer 3. Alternatively, the lead frame shown in FIG. 1 in which a plating layer formed in the order of Ni / Pd) is formed is obtained.

According to the lead frame of the first embodiment, since the second plating layer 4 is formed on the side surface and the back surface of the metal plate 10 and the back surface of the protruding portion 3-1 of the first plating layer 3. In the state in which the second plating layer 4 is integrated with the side surface and the back surface of the metal plate 10 and the back surface of the protruding portion 3-1 of the first plating layer 3. The protrusion 3-1 is reinforced and supported. For this reason, it can prevent that the protrusion part 3-1 produces a crack, a chip | tip, and falls as a burr | flash, for example, when the lead frame of 1st Embodiment is used as a lead frame for LED, during the manufacturing process of an LED package. There is no possibility that the cracked plating burr causes an electrical short circuit in the lead portion, bonding wire portion, LED element portion, or the like.
Further, according to the lead frame of the first embodiment, the first plating layer 3 is formed with the protruding portion 3-1 protruding sideward from the edge of the front surface of the metal plate 10. The front surface of the plate 10 does not remain around the first plating layer 3. As a result, in the region where the LED element is mounted on the front side of the metal plate 10, only the reflective plating layer having a high reflectivity is exposed, and the portion having a lower reflectivity than the reflective plating layer is not exposed. It is possible to prevent the reflectance of the entire mounting area from being lowered.

Further, in the lead frame of the first embodiment, if the second plating layer 4 is formed on the side surface of the protruding portion 3-1 in the first plating layer 3, the first plating layer 3 and Since the metal constituting the second plating layer 4 is different, the second plating layer can easily suppress the migration of the metal (eg, Ag) constituting the first plating layer.
Then, this configuration is applied to the LED lead frame, and a metal (for example, Ag) different from the metal (for example, Ag) constituting the uppermost layer of the reflective plating layer is formed on the side surface of the reflective plating layer (corresponding to the first plating layer 3). For example, if the second plating layer 4 made of Ni / Pd / Au or Ni / Pd) is formed, the metal constituting the uppermost layer of the reflective plating layer is formed by the metal constituting the second plating layer 4. It is possible to block the ion movement path and suppress an electrical short between the lead portion and the pad portion due to the movement of the metal ions.

  Further, according to the lead frame of the first embodiment, since the protruding portion 3-1 of the first plating layer 3 has a protruding length up to 15 μm from the edge of the metal plate 10, the protruding portion is not variably formed. As a result, there is no possibility that the plating burr cracked during the manufacturing process of the LED package will cause an electrical short circuit in the lead portion, the bonding wire portion, the LED element portion, or the like.

In the lead frame manufacturing method according to the first embodiment, it is preferably exposed by performing etching between the etching process and the resist mask having a short dissolution and peeling time. You may make it have the process of performing a roughening process with respect to the surface of the metal plate 10. FIG.
If it does in this way, the adhesiveness of the resin part when a reflector resin part and a transparent resin part are formed will improve, for example.

Second Embodiment FIG. 3 is a cross-sectional view showing a schematic configuration of a lead frame according to a second embodiment of the present invention. FIG. 4 is an explanatory view showing an example of a manufacturing process in the manufacturing method of the lead frame shown in FIG.

In the lead frame of the second embodiment, for example, as shown in FIG. 3, the first plating layer 3 is formed on the front side surface and the back side surface of the metal plate 10, and each has a protruding portion 3-1. doing.
The protrusions 3-1 protrude with a protrusion length of up to 15 μm laterally from the front surface and the edge of the metal plate 10.
The second plating layer 4 is formed on the side surface of the metal plate 10 and the surface on the metal plate 10 side in the protruding portion 3-1 of the first plating layer 3.
Other configurations are substantially the same as those of the lead frame of the first embodiment.

  The lead frame of the second embodiment configured as described above is manufactured, for example, as follows. Note that pre-processing and post-processing including chemical cleaning and water cleaning, which are performed in each manufacturing process, are well-known processing, and thus description thereof will be omitted for the sake of convenience.

  First, using a metal plate 10 (for example, Cu material) as a base material of the lead frame (see FIG. 4A), a first region is formed in each of the predetermined regions on the front side surface and the back side surface of the metal plate 10. A resist mask 6 for plating is formed, and a first plating layer 3, for example, an Ag plating layer is formed on the exposed front surface and back surface of the metal plate 10 (see FIG. 4B).

  Next, the first resist mask 6 for plating formed on both the front and back surfaces of the metal plate 10 is peeled off (see FIG. 4C).

Next, an etching resist mask 7 is formed in a predetermined region covering at least the surface opposite to the metal plate 10 of the first plating layer 3 on the front side and the back side of the metal plate 10 (see FIG. 4D).
In the example of FIG. 4D, the etching resist mask 7 is formed so as to cover the entire exposed surface of the first plating layer 3. In the step described later with reference to FIG. 4 (f), in the case of manufacturing a lead frame in which the second plating layer 4 is also formed on the side surface of the protruding portion 3-1 of the first plating layer 3. The resist mask for etching 7 is formed so as to cover only the surface opposite to the metal plate 10 among the exposed surface of the first plating layer 3 and not to cover the side surface.

  Next, an etching process is performed on regions on the front side and the back side of the metal plate 10 that are not covered with the etching resist mask 7 to form a predetermined lead frame shape. At this time, the metal plate 10 is formed so that the first plating layer 3 has a protruding portion 3-1 protruding to the side of the front side surface and the back side surface of the metal plate 10 with a protruding length of up to 15 μm. It forms (refer FIG.4 (e)).

Next, a second resist for plating covering the resist mask for etching 7 with the front and back surfaces of the metal plate 10 and the surfaces and side surfaces of the first plating layer 3 opposite to the metal plate 10. Using the mask as a mask, plating is performed, and the surface of the metal plate 10 exposed by the etching process (for example, a side surface of the metal plate 10 and a recess when the etching process includes a half-etching process); The 2nd plating layer 4 is formed in the surface at the side of the metal plate 10 in the protrusion part 3-1 of the 1 plating layer 3 (refer FIG.4 (f)).
Next, the etching resist mask 7 is removed (see FIG. 4G).
As a result, the first plating layer 3 (for example, a plating layer composed only of an Ag plating layer or a base plating / Ag plating is formed on the front side surface and the back side surface of the metal plate 10 formed in a predetermined lead frame shape. The plating layer formed in this order or the plating layer formed in the order of Ni / Pd / Au / Ag) has a protruding length of up to 15 μm laterally from the edge of the front surface and the back surface of the metal plate 10, respectively. The second plating layer is formed on the side surface (and also the concave portion) and the surface of the first plating layer 3 on the metal plate 10 side in the protruding portion 3-1. The lead frame shown in FIG. 3 in which 4 (plating layer formed in the order of Ni / Pd / Au or Ni / Pd) is formed is obtained.

  According to the lead frame of the second embodiment, the first plating layer 3 is formed on the front side surface and the back side surface of the metal plate 10, and the second plating layer 4 is formed on the side surface of the metal plate 10, In the lead frame manufacturing process, after forming the first plating layer 3, the first plating layer 3 is formed on the surface on the metal plate 10 side of the protruding portion 3-1 of the first plating layer 3. The resist mask for etching 7 formed so as to cover the second plating layer can be used as a second resist mask for plating when the second plating layer is formed. It becomes possible to simplify and reduce the cost.

In the lead frame manufacturing method of the second embodiment, preferably, the metal exposed by etching between the step of performing the etching process and the step of forming the second plating layer 4 is preferably further provided. You may make it have the process of roughening the surface of the board 10.
If it does in this way, the adhesiveness of the resin part when a reflector resin part and a transparent resin part are formed will improve, for example.
Other functions and effects are substantially the same as those of the lead frame of the first embodiment.

EXAMPLE Next, as an example of the present invention, a multi-row type LED lead frame manufactured using the lead frame manufacturing method of the above embodiment and a manufacturing example thereof will be described.

  FIG. 5 is a diagram showing a schematic configuration of a multi-row LED lead frame according to an embodiment of the present invention. FIG. 5A is a partial plan view of the arrangement of pads and lead portions in each lead frame region as viewed from the upper surface side. FIG. 4B is a cross-sectional view of the lead frame substrate taken along line AA shown in FIG. 4A, and FIG. 4C is a cross-sectional view of a lead frame with resin formed in one lead frame region. FIG. 6 is an explanatory view showing an example of a manufacturing process of the multi-row LED lead frame shown in FIG.

The lead frame of this example is a lead frame used for manufacturing an LED package manufactured by using the lead frame manufacturing method of the second embodiment. Then, as shown in FIGS. 5 (a) and 5 (b), in order to obtain a large number of LED packages at a time, individual lead frame regions composed of combinations of the pad portion 11 and the lead portion 12 (FIG. 5 (a) ) Correspond to package outlines indicated by dashed-dotted rectangles, respectively.) Are arranged in a matrix and are formed as multi-row lead frames connected via connecting portions 17, respectively.
In each lead frame region, as shown in FIG. 5C, the first plating layer 3 is formed at a predetermined position corresponding to the pad portion 11 and the lead portion 12 on the front side surface of the metal plate 10. A reflective plating layer 13a and an external connection plating layer 13b formed with the first plating layer 3 at predetermined positions corresponding to the pad portion 11 and the lead portion 12 on the back surface of the metal plate 10 are provided. Yes.

The first plating layer 3 has projecting portions 3-1 projecting with a projecting length of up to 15 μm laterally from the edges of the front and back surfaces of the metal plate 10. Moreover, the 1st plating layer 3 is comprised by the plating layer formed in order of Ni / Pd / Au / Ag.
In addition, you may comprise the 1st plating layer 3 by the plating layer which consists only of Ag plating layers, or the plating layer formed in order of base plating / Ag plating.
Furthermore, it is preferable that the Ag plating layer formed on the uppermost layer of the first plating layer 3 constituting the reflective plating layer 13a is composed of a bright Ag plating layer.
The first plating layer 3 constituting the external connection plating layer 13b may be formed of a plating layer formed in the order of Ni / Pd / Au.

Further, the side surface of the pad portion 11 and the lead portion 12 formed on the metal plate 10 by etching, the side surface of the connecting portion 17, the concave portion formed by half-etching, the reflective plating layer 13a and the external connection plating A second plating layer 4 is formed on the metal plate 10 side surface and the side surface of each protrusion 3-1 of the layer 13b.
The second plating layer 4 is composed of a plating layer formed in the order of Ni / Pd.
In addition, you may comprise the 2nd plating layer 4 by the plating layer formed in order of Ni / Pd / Au.
Further, the multi-row LED lead frame of the present embodiment is partitioned from the metal plate 10 into a pad portion 11 and a lead portion 12 each having a connecting portion 17 by through etching and half etching. In addition, the lead frame region is divided into another lead frame region adjacent to the lead frame region. The pad portion 11 and the lead portion 12 are separated in each lead frame region. In FIG. 5A, reference numeral 18 denotes an outer frame portion in the metal plate 10 for manufacturing a multi-row lead frame.

  In FIG. 5C, reference numeral 15 denotes a reflector resin portion provided after the multi-row LED lead frame of this embodiment is formed. The reflector resin portion 15 is in close contact with the side surfaces of the pad portion 11 and the lead portion 12, the entire surface of the connecting portion 17, and a recess formed in the connecting portion 17 by half etching. The reflector resin portion 15 covers the connecting portion 17 and is interposed between the pad portion 11 and the lead portion 12 so as to be flush with each other, and the outer periphery of the pad portion 11 and the lead portion 12 is disposed on the pad portion 11. The LED element mounting surface surrounds the LED element so as to protrude upward.

  The multi-row type LED lead frame of this example configured as described above was manufactured as follows, for example. Note that pre-processing and post-processing including chemical cleaning and water cleaning, which are performed in each manufacturing process, are well-known processing, and thus description thereof will be omitted for the sake of convenience.

First, a Cu-based material having a strip shape and a thickness of 0.2 mm was prepared as a metal plate 10 that forms the base material of the lead frame (see FIG. 6A), and pilot holes were formed at the edge of the outer frame portion. Then, a resist layer was formed on both front and back surfaces using a dry film resist.
Next, a glass mask on which a pattern necessary for obtaining a resist mask for forming a reflective plating layer is prepared on the front surface of the base material of the lead frame, and an external surface is provided on the back surface. Prepare a glass mask on which a pattern necessary for obtaining a resist mask for forming a plating layer for connection is drawn, and determine the position of the glass mask based on the pilot holes formed earlier, and perform exposure and development. Thus, the first resist mask 6 for plating was formed on both the front and back surfaces of the base material of the lead frame.
Next, the first plating layer 3 is formed in the exposed regions of the lead frame base material that are not covered with the first plating resist mask 6 on both the front and back surfaces (see FIG. 6B). After forming the first plating layer 3, the first resist mask 6 for plating formed on the front and back surfaces was peeled off (see FIG. 6C).
The first plating layer 3 is formed by first forming Ni plating with a set thickness of 2.0 μm, forming Pd plating with a set thickness of 0.03 μm thereon, and then forming Au with a set thickness of 0.01 μm. A plating was formed, and finally, an Ag plating with a set thickness of 2.0 μm was formed.
In addition, the 1st plating layer 3 can also be obtained by forming the layer of Ag plating 2.0 micrometers, or the lamination of Cu strike plating 0.1 micrometer and Ag plating 2.0 micrometers.

Next, a resist layer is formed on the front side and the back side of the lead frame base material using a dry film resist, exposed and developed, and the resist mask 7 is at least the lead frame base material in the first plating layer 3. It formed in the predetermined area | region which covers the surface on the opposite side.
Next, an etching process is performed using an etching solution, the pad portion 11 and the lead portion 12 are formed in a predetermined shape each having a connecting portion, and the pad portion 11 and the lead portion 12 are penetrated. The lead frame region and the other lead frame region adjacent to each other were provided with a connecting portion 17 to form a lead frame shape (see FIG. 6D).
In addition, the depth of the half etching which divides each outer periphery of the pad part 11 and the lead part 12 in the connection part 17 was about 0.12 mm.
The reflective plating layer 3 is formed in a shape having a protruding portion 3-1 protruding sideways with a protruding length of 15 μm from the edge of the front surface and the back surface of the pad portion 11 and the lead portion 12. It was.

Next, the surface and side surfaces of the lead frame on the base side in the protrusions 3-1 of the first plating layer 3 formed on the front side surface and the back side surface of the base material of the lead frame are etched. A second plating layer 4 was formed on the side surface of the base material of the lead frame exposed by this and the concave portion on which the half etching was performed on the base material of the lead frame (see FIG. 6E).
The second plating layer 4 was obtained by forming Ni plating with a set thickness of 3.0 μm and forming Pd plating with a set thickness of 0.03 μm thereon.
The second plating layer 4 can also be obtained by forming a laminate of Ni plating with a set thickness of 2.0 μm, Pd plating with a set thickness of 0.03 μm, and Au plating with a set thickness of 0.01 μm. .

  Next, the resist mask 2 remaining on the front side and the back side is peeled off by being immersed in a dissolving stripping solution, and predetermined positions corresponding to the pad portion 11 and the lead portion 12 on the front side surface and the back side surface of the base material of the lead frame. In addition, a Ni plating layer, a Pd plating layer, an Au plating layer, an Ag plating layer, or a plating layer composed of only an Ag plating layer, or a Cu plating layer and an Ag plating layer are formed in this order. 3 is formed, and Ni plating is sequentially applied to the side surface and the side surface of the lead frame on the side surface of the lead frame base material, the half-etched recess, and the protrusion 3-1 of the first plating layer 3. A reflector resin portion 15 shown in FIG. 5C is provided in which a second plating layer 4 is formed by forming a layer and a Pd plating layer, or a Ni plating layer, a Pd plating layer, and an Au plating layer in this order. To obtain a multi-row type LED lead frame with the step pad portion 11 and the lead portion 12 with connecting portion 17 (see FIG. 6 (f), the FIG. 6 (g)).

Next, the manufacturing process of the lead frame with a resin and the semiconductor device using the lead frame manufactured by the manufacturing method of the lead frame of the present invention will be described.
FIG. 7 is an explanatory view showing an example of the manufacturing process of the resin-equipped multi-column LED lead frame and LED package using the multi-column LED lead frame obtained through the manufacturing process shown in FIG.
First, a reflector resin is filled between the lead portion 12 and the pad portion 11 of the LED lead frame using a mold, the front side and back side half-etched portions, and other necessary portions are filled with the reflector resin. Resin portion 15 is formed to obtain a resin-attached multi-row LED lead frame (see FIG. 7A).

Next, the LED element 20 is mounted and fixed on the pad portion 11 of the LED lead frame on which the reflector resin portion 15 is formed (see FIG. 7B), and the LED element 20 and the lead portion 12 are wire-bonded. (Refer to FIG. 7 (c)) Further, the transparent resin portion 16 for sealing the LED element 20 and the bonding wire 14 is filled with a transparent resin in the internal space in which the LED element 20 surrounded by the reflector resin portion 15 is mounted. It forms (refer FIG.7 (d)).
Next, the part surrounding the outer periphery of the pad part 11 and the lead part 12 in the reflector resin part 15 is cut together with the connecting part 17. Thereby, the LED package is completed.

  The lead frame and the manufacturing method thereof of the present invention are useful in a field where it is necessary to perform etching after plating a metal plate.

3 First plating layer 3-1 Protruding portion 4 Second plating layer 6 First plating resist mask 7 Etching resist mask 8 Second plating resist mask 10 Metal plate (lead frame substrate)
DESCRIPTION OF SYMBOLS 11 Pad part 12 Lead part 13a Reflective plating layer 13b External connection plating layer 14 Bonding wire 15 Reflector resin part 16 Transparent resin part 17 Connection part 18 Outer frame part 20 LED element

The formation of the resist mask used in the manufacturing process of the lead frame of this embodiment and later embodiments, for example, the front surface and the back surface of the metal plate, laminating a their respective De Lai film resist, both sides The dry film resist is exposed and developed on both the front and back surfaces using a glass mask having a predetermined lead frame shape pattern formed at a predetermined position. Exposure and development are performed by a conventionally known method. For example, by irradiating ultraviolet rays in a state covered with a glass mask, reducing the solubility of the dry film resist portion irradiated with the ultraviolet rays that passed through the glass mask with respect to the developer, and removing other portions, A resist mask is formed. Here, a negative dry film resist was used as the resist. However, for the formation of the resist mask, a positive dry film resist was used to develop a portion of the resist irradiated with ultraviolet rays that passed through the glass mask. The resist mask may be formed by increasing the solubility in the liquid and removing the portion.

In the lead frame manufacturing method of the first embodiment, it is preferable that the metal plate 10 exposed by performing etching between the etching process and the etching resist mask removal process. You may make it have the process of performing a roughening process with respect to this surface.
If it does in this way, the adhesiveness of the resin part when a reflector resin part and a transparent resin part are formed will improve, for example.

First, a Cu-based material having a strip shape and a thickness of 0.2 mm was prepared as a metal plate 10 that forms the base material of the lead frame (see FIG. 6A), and pilot holes were formed at the edge of the outer frame portion. Then, a resist layer was formed on both front and back surfaces using a dry film resist.
Next, a glass mask on which a pattern necessary for obtaining a resist mask for forming a reflective plating layer is prepared on the front surface of the base material of the lead frame, and an external surface is provided on the back surface. Prepare a glass mask on which a pattern necessary for obtaining a resist mask for forming a plating layer for connection is drawn, and determine the position of the glass mask based on the pilot holes formed earlier, and perform exposure and development. Thus, the first resist mask 6 for plating was formed on both the front and back surfaces of the base material of the lead frame.
Next, the first plating layer 3 is formed in the exposed regions of the lead frame base material that are not covered with the first plating resist mask 6 on both the front and back surfaces (see FIG. 6B). after forming the first plating layer 3 was peeled off the first plating resist mask 6 formed on both sides by by Ri swelling stripping solution (see Figure 6 (c)).
The first plating layer 3 is formed by first forming Ni plating with a set thickness of 2.0 μm, forming Pd plating with a set thickness of 0.03 μm thereon, and then forming Au with a set thickness of 0.01 μm. A plating was formed, and finally, an Ag plating with a set thickness of 2.0 μm was formed.
In addition, the 1st plating layer 3 can also be obtained by forming the layer of Ag plating 2.0 micrometers, or the lamination of Cu strike plating 0.1 micrometer and Ag plating 2.0 micrometers.

Next, by immersion in exfoliation solution, the resist mask 2 remaining on the front side and the back side was peeled swollen, corresponding to the pad portion 11 and the lead portion 12 in the front surface and the back surface of the base material of the lead frame A first plating layer in which a Ni plating layer, a Pd plating layer, an Au plating layer and an Ag plating layer, or a plating layer consisting of only an Ag plating layer, or a Cu strike plating layer and an Ag plating layer are formed in this order. The plating layer 3 is formed, the side surface of the lead frame base material, the half-etched concave portion, and the surface and side surfaces of the protrusion portion 3-1 of the first plating layer 3 on the base material side of the lead frame, The reflector resin portion 15 shown in FIG. 5C is formed with the Ni plating layer and the Pd plating layer in order or the second plating layer 4 formed by sequentially forming the Ni plating layer, the Pd plating layer, and the Au plating layer. Provided To obtain a multi-row type LED lead frame with a connecting portion 17 with the pad portion 11 and the lead portion 12 of the preceding stage which are (see FIG. 6 (f), the FIG. 6 (g)).

Claims (11)

On the front side surface of the metal plate, a first plating layer having a protruding portion that protrudes laterally from an edge of the front side surface of the metal plate is formed,
A lead frame, wherein a second plating layer is formed on a side surface and a back surface of the metal plate and at least a back surface of the protruding portion of the first plating layer. On the front side surface and the back side surface of the metal plate, a first plating layer having protrusions protruding laterally from the edges of the front side surface and the back side surface of the metal plate is formed, respectively.
A lead frame, wherein a second plating layer is formed on a side surface of the metal plate and at least a surface of the protruding portion of the first plating layer on the metal plate side. The first plating layer is a plating layer having Ag as a top layer;
The lead frame according to claim 1 or 2, wherein the second plating layer is a plating layer formed in the order of Ni / Pd / Au or Ni / Pd.   The lead frame according to claim 1, wherein the protruding portion of the first plating layer has a protruding length of 15 μm from an edge of the metal plate.   The lead frame according to claim 1, wherein a side surface of the metal plate is roughened. Forming a first resist mask for plating on both front and back surfaces of the metal plate;
Forming a first plating layer on the surface of the metal plate after forming the first resist mask for plating; and
Removing the first resist mask for plating after forming the first plating layer;
After removing the first plating resist mask, forming a resist mask for etching on the front side and the back side of the metal plate so as to cover at least the first plating layer;
After forming the etching resist mask, etching is performed on the front and back sides of the metal plate that are not covered with the etching resist mask, and the first plating layer is formed on the front side of the metal plate. Forming the metal plate so as to have a protruding portion that protrudes laterally from the edge of the surface;
Removing the etching resist mask after the etching process;
Forming a second resist mask for plating covering the front side surface of the metal plate and at least the front side surface of the first plating layer after removing the etching resist mask;
After forming the second resist mask for plating, a second plating layer is formed on the side surface and the back surface of the metal plate and at least the back surface of the protruding portion of the first plating layer. Process,
Removing the second plating resist mask after forming the second plating layer;
A method for manufacturing a lead frame, comprising: Forming a first resist mask for plating on both front and back surfaces of the metal plate;
Forming the first plating layer on the front side surface and the back side surface of the metal plate after forming the first resist mask for plating; and
Removing the first resist mask for plating after forming the first plating layer;
After removing the first plating resist mask, forming a resist mask for etching on the front side and the back side of the metal plate so as to cover at least the front side surface of the first plating layer;
After forming the etching resist mask, etching is performed on the front and back sides of the metal plate that are not covered with the etching resist mask, and the first plating layer is formed on the front side of the metal plate. Forming the metal plate to have protrusions protruding laterally from the edges of the surface and the back surface, respectively,
A step of forming a second plating layer on the side surface of the metal plate and at least the metal plate side surface of the protruding portion of the first plating layer after the etching process;
Removing the etching resist mask after forming the second plating layer;
A method for manufacturing a lead frame, comprising: The first plating layer is a plating layer having Ag as a top layer;
8. The lead frame manufacturing method according to claim 6, wherein the second plating layer is a plating layer formed in the order of Ni / Pd / Au or Ni / Pd.   The lead frame manufacturing method according to claim 6, wherein the protruding portion of the first plating layer has a protruding length of 15 μm from an edge of the metal plate.   Furthermore, between the step of performing the etching process and the step of removing the resist mask for etching, a step of performing a roughening process on the surface of the metal plate exposed by the etching. The method of manufacturing a lead frame according to claim 6, wherein   Furthermore, between the process of performing the said etching process, and the process of forming the said 2nd plating layer, it has the process of performing the roughening process with respect to the surface of this metal plate exposed by the said etching. The method of manufacturing a lead frame according to claim 7.

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